Testing system



L. J. BOWNE TESTING SYSTEM Filed March 10, 1923 lnven/or: v Lang/"0rd J.Bow/7e Airy Patented June 2, 1925.

UNITED STATES PATENT o c LANGFORD J. BOWNE, OF HOWARD BEACH, NEVT YORK,ASSIGNOR TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, N.Y., A CORPORATION OF NEW YORK.

TESTING SYSTElVL.

Application filed March 10, 1923. Serial No. 624,105.

To all whom it may concern:

Be it known that I, LANGFORD J. BOWNE, a citizen of the United States,residing at Howard Beach, in the county of Queens, State of New York,have invented certain new and useful Improvements in Testing Systems, ofwhich the following is a full, clear, concise, and exact description.

This invention relates to testing systems and more particularly tosystems for testing and adjusting apparatus used in signaling overtelephone line circuits.

It is sometimes desirable to employ signaling current of one charactersuitable for transmission over the line from a distant station and toprovide at the receiving station a relay or other means responsive thereto for translating such signaling current into current suitable foroperating the signaling apparatus thereat.

As the translating means must be responsive to incoming current of theproper character, but unresponsive to current of other character, whichmay be impressed on the line, such, for example, as impulses caused by acalling subscriber attempting to recall the operator by working theswitchhook of his telephone up and down, it is desirable to providemeans for readily testing such translating means under such conditionsin order that any necessary adjustments may be made to insure itsnonresponse to such improper currents but its response to currents ofthe proper cha 'acter.

It is an object of this invention to provide an improved method andmeans for testing translating means associated with telephone lines ofthe aforementioned character.

This object is attained in accordance with a feature of the invention bythe provision of switching means so that such signaling apparatus ortranslating means may be dis connected from the line circuit andsubjected to electrical conditions simulating those under which thetranslating means should not respond,'suitable signaling means beingprovided for indicating the operation of such translating means underthese conditions. i

In accordance with another feature of the invention an automatictelephone impulse sender of the usual type is employed for generatingthe current impulses which simulate the current impulses to which it isdesired the translating means shall not respond. 1

In accordance with still another feature of the invention,electromagnetic means are provided and so arranged in association withthe impulse sender that a fewer number of impulses are transmitted tothe translating means than the number of times the inipulse sender makesand breaks its pulsing contact. Other and further features will beapparent from the following description when read in connection with theaccompanying drawing which shows diagrammatically one embodiment of theinvention. Referring to the drawing the apparatus shown above and to theright of the dotted line and designated as A represents, what iscommonly known as, a composite ringer set which may be connected betweena transmission line and an exchange switchboard by means of cords andplugs C and G which are adapted to be inserted in jacks J and J, so thatthe conductors 1 and 2 will connect with the line and conductors 3 and 4with the switchboard. Conductors 1 and 3are normally connected by meansof conductor 7 and conductors 2 and 4 by means of conductor 8 throughthe normal contacts and armatures of relays 5 and 6.

Bridged across the conductors 7 and 8 through the retardation coils 9and 10 are the relays 11 and 12, relay 11 being adjusted to respond toringing currentof a frequency similar to that of the current of theswitchboard, which in practice may be 20 cycles and relay 12 beingadjusted to respond only to ringing current having a frequency similarto that of the ringing current transmitted over the transmission line,which in practice, might be 135 cycles. Accordingly, ringing currentsent out from the switchboard over conductorsS and 4 will cause relay 11to operate, but relay 12 will not operate as it is adjusted to respondto current of a different frequency and ringing current coming in overthe line to conductors 1 and 2 will cause the relay 12 to operate butwill not afiect relay 11 as it is adjusted to respond to current of alower frequency.

The operation of relay 12 causes the release of relay 13 which in turncauses relay 6 to operate to disconnect the ringer set from theswitchboard conductors and to ap ply 20 cycle ringing current thereto,and the operation of relay 11 causes the operation of relay 5 whichdisconnects the ringer set from the line and applies cycle ringingcurrent thereto from the source lat. The operation of relay l1 alsocloses a circuit for the' operation of relay which in sures thecontinued energization of relay 13 during the ringing interval. I

It frequently happens that inductive disturbances or false currentimpulses are set up in composited trunk lines which tend to affect relay12 and cause it tochatter sufficiently to allow relay 13 to release,thus causing afalsering to be transmittedtothe switchboard. It has beenfound that one of the principal causes ofthese false currents in systemsof thischaracter is the genera tion of impulses by the operation of theswitchhook of a subscribers .set in an attempt to signal the operator atthe exchange when the subscribers set is connected through atollswitching trunk and a toll cord circuit with such a composited trunkline. It, therefore, is, apparent that the relay -12 should be .soadjusted that it will not respond to such false impulses but willrespond to regular ringing impulses of. the selected frequency;

Again referring to the drawing, the apparatus and circuits to the leftand, below the dottedv line designated as B represents the testingsystem of the, present invention which is adapted to be connected to thecom.- posite ringer A by means of the, jacks J and J and the cord-s Cand C Connected across the springs 16 and 17 of the jacks J 2 and J,respectively, is a. relay 18 responsive to. 20 cycle ringing current)which controls through its armature and alternate contact.

a signaling device such as a bell 19. Connectednacross the springs 20and 21, of the jacks J, and J, is apparatus for generating currentimpulses which simulate the switchhook impulses before mentioned whichcomprises a transformer 23', sources of. current 2% and 25, and an,impulse senderi22 of well.

known type, which is adapted to be connected'with achain of relays 26,27, 28 and 29 by means of plug P and jack J,.

The invention will bemore fully understood from the followingdescription of 013% eration. To test the relay 12 against switchhool:impulses, that is, to supply impulses simulating. those generated by thesub scribefis switchhook when moved up and down in an attempt to signalthe operator, jacks J and J, are connectedby means of cordC and J and Jby means of cord (3,; Plug: P is inserted intojaclt J, and the dial (notshown) of the impulse sender 22 is ro tated to the right and released inthe well known manner. On the closure ofthe shunt contact 5500f thesender relay 32 is operated in a circuit from grounded vba tter'y 31winding of relay 32, conductor 33, sleeve contacts ofijack J and plug P,shunt contact and pulsing contact 34; of sender 22, tip contacts of plugP and jack J and upper armature and normal contact of relay 26 toground. A circuit is also prepared at this time for the operation ofrelay 26 from grounded battery 31, relay 32, conductor 33,.sleev'e contacts of jack J and plug P, shunt contact 30', ring contacts of P and J,and winding of relay, 2:6 to ground. Relay 26, however, does not operateat this time because it is short circuited by its upper normal con tactand thepulsiug contact 34.

Relay 32 in operating connects the output circuit of the simulatedswitching trunk,

with the line. side of the composite ringer set A over conductors 4:6and 47, jacks J and J and cords G andC On thefirst break of,- thepulsing contact ofsender 2, relay 26 operatesand transfers the circuitof the pulsing contact, from the upper normal contact of relay 26 to thewinding of relay 2? which circuit may be traced from pulsing contactspring EMA, tip contacts ofjplug P and jack J upper armature andalternate contact of relay, 26., con ductor 36, lower normal contact 37,of relay 29, eonductor 38, upper normal contact 39 of relay 28 andwinding of relay 2? toground; Relay however, does not operate at thistime as the pulsing contact 3a is open. Relay 26- in operatingalsoclosed a, circuit from grounded battery 24-through the upe per windingof retardation coil; -10, lower alternatecontact 41 of relay 26, uppernormal contact 42 of; relay 43, winding 4 of transformer 23, upperalternate contact of relay 32,- conductor. 46, spring 20 of. jack J tipconductor of cord C, tip spring of jack J, conductor 1, upper, normalcontact ofrelay 5, conductor, 7, retardation coil 9, winding of relay12, conductor 8-, lower normal contact of relay conductor 2, ring springof aclt J ring conductor of cordC spring 21 of jack J conductor 47,armature and lower alternate contact of relay. 3.2, winding 48 oftransformer 23-, mal contact of. relay 43, and. lower winding ofretardation coil 1-0 to ground; This causes a surge of current to flowin the circuit just traced and causes a current pulse in relay 12 whichtends to energize the relay;

On the first make of. the pulsing contact- 34 after the first break,relay 2'? operates in the circuit which may be traced from groundedbattery 31 winding of relay 32. conductor, 33, sleeve contacts of J,and, P, shunt contact 30 of sender 22, pulsing contact 34L, tip contactsof P and J upper alternate contact of relay 26, conduct'OlV 36, lowernormal contact 37 of; relay 29, conductor 38, upper normal contact 39 ofrelay 28 and winding of relay 2? to ground. Relay 2? inoperating closesa circuit for relay 28 which may be traced lower nora from groundedbattery 31, winding of relay 32, conductor 33, sleeve contacts of J, and

I, shunt contact J sender 22, ring contacts of P and .L, conductor 49,upper normal contact of relay 29, winding of relay 28, upper alternatecontact of relay 27 winding of relay 27 to ground. Relay 28, however,does not operate at this time as it is shunted by the pulsing contact34. Relay 27 in operating closes at its lower alternate contact acircuit through the windings 50 and 51 of the transformer 23, battery25, and relay 52 which causes a surge of current to be induced in thewindings 44 and 48 of the transformer 23 which iiows over the circuitbefore traced to the composite ringer and causes another energizingpulse in the wind-V ings of relay 12. Relay 52 in operating closes acircuit through relay 43 which may be traced from grounded battery,winding of relay 43, conductor and upper alternate contact of relay 52to ground. Relay 43 in operating opens at its upper and lower normalcontacts the circuit for battery 24, before traced, thus causing a thirdsurge of current in the winding of relay 12.

On the second break of the pulsing con tact 34, relay 28 operates as theshort circuit around this relay is opened by the breaking of thiscontact but relay 27 is held operated as the energizing circuit forrelay 28 is completed through the winding of relay 27. Relay 28 inoperating transfers the pulsing contact circuit from the winding ofrelay 27 to the winding of relay 29 which circuit may be traced fromspring 34A of sender 22, tip contacts of P and J upper alternate contactof relay 26, conductor 36, lower normal contact 37 of relay 29, upperalternate contact of relay 28, and winding of relay 29 to ground. On thenext make of the pulsing contact relay 29 operates in a circuit whichmay be traced from grounded battery 31, winding of relay 32, conductor33, sleeve contacts of J, and P, shunt contact 30 of sender 22, pulsingcontact 34, tip contacts of P and J upper alternate contact of relay 26,conductor 36, lower normal contact 37 of relay 29, conductor 38 upperalternate contact of relay 28, winding of relay 29 to ground. Relay 29in operating opens the circuit for the windings of relay 27 and 28 atits upper normal contact. Relay 29 in operating also closes its loweralternate contact 53, thus preventing the relay from releasing whenrelay 28 is deenergized. Relay 29 in closing its lower alternate contact53 establishes a direct energizing circuit from pulsing contact 34, tipcontacts of P and J upper alternate contact of relay 26, conductor 36,lower alternate contact 53 of relay 29 and winding of relay 29 toground. Relay 27 in releasing opens the circuit previously tracedthrough the windings 50 and 51 of a transformer 23, battery 25 and relay52 which causes a surge of current to be induced in the windings 44 and48 which in turn causes a fourth pulse through the relay 12. On theopening of the pulsing contact after the second make relay 29 re leases.On the third make of the pulsing contact the chain of operationsdescribed for the first make of the pulsing contact is re peated. Thesefour current pulses i. e., on the closure of the lower alternate contactof relay 26, closure of the lower alternate contact of relay 27 theoperation of relay 43 and the opening of the lower alternate contact ofrelay 27, are approximately equivalent to the impulses caused by theaverage subscribers working of the switchhook in an attempt to signalthe operatqr, when the subscribers telephone is connected through a tollswitching trunk and a toll and circuit to a composite trunk line.

When the dial (not shown) of sender 22 is operated to its extremeposition and released, it makes and breaks the pulsing con tact 34 tentimes thus causing the chain of operations just described to functionfive times and sending five sets of impulses into relay 12 which may besufficient if the relay is not properly adjusted to cause its armatureto vibrate and allow its controlled relay 13 to release thus causing theenergization of relay 6 and the connecting of ringing current from thesource 54 to the conductors 3 and 4 which are connected by means ofcords O and O, to the springs 16 and 17 across which is connected therelay 18 which is responsive to such ringing current, thus causing theactuation of the signaling device 19 which signifies to the testoperator that the relay 12 has operated and therefore the compositeringer set is in need of adjustment.

When the dial returns to normal the shunt contact 30 opens and releasesall relays thus restoring the equipment to normal.

It will be obvious that the general principles herein disclosed may beembodied in many other organizations quite different from thoseillustrated, without departing from the spirit of the invention asdefined by the following claims.

What is claimed is:

1. A testing system comprising electro-responsive means to be tested,means for generating and transmitting electrical impulses simulatingthose generated by the operation of the switchhook in a subscriberstelephone set when it is connected through a toll switching trunk and atoll cord circuit with a line, switching means for connecting saidgenerating means with said electro-responsive means, and means forindicating the response of said electro-responsive means, saidgenerating means comprising an au tomatic telephone impulse sender and aplurality of relays so arranged that a different numberot' impulses aretransmitted to the 'translating device under test than the number oftimes the pulsing contact of the impulse sender is made and broken.

2. In a testing: systei in combination, a relay to be tested, a circuithaving a transformer therein, a source of direct current, an impulsesender adapted to make and break a circuit a number of times when 01erated and released, a plurality of relays controlled by said impulsesender and adapted to connect said currentsource to a Windof saidtransformer means for connecting said transtor. 181 to the winding ofthe relay to be tested and means for indicating the response of saidrelay. i I

3. In a testing systenn'in combinatiom a relay to be tested, a circuitcomprising a transformer, a source of direct current, an

impulse sender adapted to make and break a circuit a number of timeswhen operated and released, a plurality of relays controlled by saidimpulse sender and adapted to (302% nect said direct current source to aWinding of said transformer. and also to disconnect said source fromsaid transformer Winding to set up in the output of said trans former aseries of impulses fewer in number than the number of? times the pulsingcontact of the impulse sender is made and broken, means for connectingsaid transformer to the Winding of said relay to be d, and means forindicating: theresponse of said relay.

In witness whereof I hereunto subscribe my name this 8th day of March A.D.,

LANGFORD J. BOVNE.

